From Siemens Medical Systems;

FDA cleared and CE Mark 2011.
The Biograph mMR has a fully-integrated design for simultaneous PET/MRI imaging. The dedicated hardware includes solid-state, avalanche photodiode PET detector and adapted, PET-compatible MR coils.
The possibility of truly simultaneous operation allows the acquisition of several magnetic resonance imaging (MRI) sequences during the positron emission tomography (PET) scan, without increasing the examination time.
See also Hybrid Imaging.

Quick Overview

Radio frequency quadrature artifacts occur when the detector channels of the quadrature detector are disturbed.
A DC offset of one amplifier output can e.g., produce a bright point in the center of the field of view (see also central point artifact), or a higher gain of one detector channel can generate diagonally ghosting.

Radio frequency quadrature artifacts are technical faults and must be eliminated by the service.

Another term for detector, by analogy to broadcast radio receivers. Other terms used for devices of this type include modulators, phase sensitive detector and mixers.

A RF coil, often a transmit receive coil with a number of wires running along the z-direction, arranged to give a cosine current variation around the circumference of the coil, which looks like a bird cage. The bird cage coil works on a different principle to conventionally tuned local and surround coils in that it behaves like a tuned transmission line with one complete cycle of standing wave around the circumference. The frequency supply is generated by an oscillator, which is modulated to form a shaped pulse by a product detector controlled by the waveform generator. The signal must be amplified to 1000's of watts. This can be done using either solid state electronics, valves or a combination of both.
The bird cage coil design provides the best field homogeneity of all RF imaging coils.
One advantage is that it is simple to produce an exceedingly uniform B1 radio frequency field over most of the coil's volume, with the result of images with a high degree of uniformity.
A second advantage is that nodes with zero voltage occur 90° away from the driven part of the coil, thus facilitating the introduction of a second signal in quadrature, which produces a circularly polarized radio frequency field.
This type of volume coil is used for brain (head) MRI, or MR imaging of joints, such as the wrist or knees.

See also the related poll result: '3rd party coils are better than the original manufacturer coils'

MRI computer can be divided into central processing unit (CPU), consisting of instruction, interpretation and arithmetic unit plus fast access memory, and peripheral devices such as bulk data storage and input and output devices (including, via the interface, the spectrometer). The computer controls the RF pulses and gradients necessary to acquire data, and process the data to produce spectra or images. (Devices such as the spectrometer may themselves incorporate small computers.)

See also Digital to Analog Converter, Analog to Digital Converter, Transformer, Pulse Programmer, Array Processor, Detector.

See also the related poll result: 'Most outages of your scanning system are caused by failure of'